What is essential for a TERT leader before departing to a deployment area?

Securing a resource number from the State Emergency Management Agency is crucial for a TERT leader before departing to a deployment area because this number is typically essential for coordination and resource allocation. The resource number serves as a formal identification that links the team to the state's emergency management framework, ensuring that the team is recognized and can be supported during a deployment. This number facilitates communication with other emergency services and allows the team to access necessary resources, including logistics, personnel support, and operational directives.

While the other choices may have their importance, they do not carry the same level of necessity in ensuring institutional backing and operational accountability as the resource number does. Having a detailed personal travel itinerary, a list of previous deployments, or signed waivers from team members can all contribute to the overall organization and safety of a deployment, but they do not establish the team's official status and operational legitimacy in the deployment area in the same way that a resource number does.